Coupling



Feb. 14, 1939. L. RICEFIELD COUPLING 26, 19:57 2 sheets-sheet 1 Filed Nov Feb. 14, l939 v L. RICEFIELD 2,146,766

COUPLING Filed Nov. 2e, 1957 2 sheet-sneez 2 lPatented Feb. 14, 1939 3 Claims.

This invention relates to improvements in couplings for connecting substantially aligned shafts and its purpose is to provide an improved device of simple form, and capable of' being 5 manufactured at small cost, which will compensate for angular misalignment, relative lateral displacement and relative endwise movement of -two connected shafts.

The improvement is particularly useful for l connecting shafts of small size through which a small amount of power is to be transmitted and which have their adjacent ends spaced a substantial distance apart. An attempt has heretofore been made to meet the requirements of this type of service by providing a coupling comprising two coupling members, adapted to be securedto the two shafts, and connected byv an intermediate flexible member, or hose, formed of rubber or the like, which is capable of ,stretching and becoming distorted to compensate for faulty alignment or relative endwise movement of the shafts. These prior devices have-*been unsatisfactory in use because the intermediate flexible member, being of substantial length, has been distorted angularly to an excessive degree by the torsional stresses transmitted therethrough with a resulting stretching of the fibers of the material and a shortening ofthe effective length of the member as a whole, thereby drawing the connected shafts toward each other and producing end thrusts on bearings and the like. These conditions have resulted in a rapid deterioration of the coupling and of the shaft bearings.

The principal object of the present invention is to overcome the above mentioned diiliculties and others by providing an improved coupling comprising a pair of couplingl members adapted to be attached to the ends of two shafts and having interposed between them an intermediate member of hard material which is flexiblyconnected to them by rings of soft material adapted to be distorted to compensate for lack of alignment of the shafts. A further object is to provide an improved coupling of this type in which an intermediate member of hard material and having substantial length is connected to the coupling members yby relatively thin rings 'of resilient deformable material capable of compenvsating for lack of alignment of the lshafts with- 59 out producing distortion of the intermediate member and without causing substantial end thrust upon the connected shafts. Still another object offthe invention is to provide a exible coupling comprising a pair of unyielding coupling mem- 55 bers adapted lto be attached to a pair of substantially aligned shafts., in combination with an intermediate member of hard material connected to the coupling membersby rings of rubber or the like which are vulcanized to or otherwise permanently attached to the intermediate member andthe coupling members. Another object of the invention is to provide a coupling comprising two coupling members of hard materialadapted to be mounted upon the ends of two substantially 'aligned shafts and `having interposed between l() them an intermediate member of hard material and two connecting rings of relatively soft deformable material, one of the coupling members having means for permitting relative endwise movement thereof with respect to the .shaft on which it is mounted. Other objects relate to various features of construction andv arrangement which will appear more fully hereinafter.

The nature of the invention will be understood from the following specification taken with the accompanying drawings iniwhich several embodiments of the invention are illustrated. In the drawings, l

Figure 1 shows a longitudinal axial section through one form of coupling embodying the present invention, the shafts upon which the coupling members are mounted being shown in elevation;

Fig. 2 is a sectional view similar to that of Fig'. 1 showing th'e relative positions of the parts 30 when there is a. substantial lateral displacement of the connected shafts;

Fig. 3 shows a longitudinal axial section through a modied form of the invention in which the ends of the intermediate member surround 'portions of the coupling members;

Fig. 4 is a sectional view showing the relative positions of the parts of the coupling illustrated in Fig. 3 when there is a substantial lack of alignment of the two connected shafts;

Fig. 5 shows a longitudinal axial section through another form of coupling embodying the present invention, wherein means are provided for permitting relative longitudinal movement of one of the coupling members uponvone of the shafts; l

Fig. 6 `shows a `longitudinal axial section through the coupling illustrated in Fig. 5 when the shafts and the connecting parts have been removed; I

Fig. 7 shows an end elevation of the righthand coupling member illustrated in Fig. 6 showing the longitudinal grooves through which a connection is'made with the shaft; and

Fig 8 shows an end elevation of the right- 4 hand shaft shown in Fig. 5 with the toothed driving member mounted thereon.

The form of theinvention illustrated in Figs. 1 and 2 of the drawings comprises a pair of coupling members Ill and II formed of vhard material, such as steel, brass, hard rubber, or the like, and having central cylindrical bores which are engaged bythe shafts I2 and I3, respectively. The shafts are commonly flattened at their ends as shown at I2a and I3B to provide surfaces which may be engaged by the inner ends of the set screws I4 which are mounted in threaded apertures in the coupling members for securing them in fixed positions on the shafts. The coupling members I and II are connected by an intermediate power transmitting member I5 and two similar connecting members or rings I6, all

of which are of circular cross section with'central apertures therethrough. The member I5 is adapted to be formed of hard material, such as steel, brass, hard rubber or, the like, which will be substantially incompressible and not subject.

to distortion under the influence of the forces which are transmitted from one coupling member to the other. The connecting members I6 are preferably formed of. soft rubber or rubber which is reinforced by textilefabric or the like, or other similar deformable material which is resilient and relatively soft so that it is capable of being compressed and distorted to compensate for lack of alignment of the two shafts I2 and I3. These connecting rings I6 are preferably vulcanized on their 4end surfaces to the end sur-v faces of the coupling members I0 and II and the intermediate member I5, thus providing in effect, an integralv construction for the' entire coupling while securing the advantage of employing an intermediate member I5 which is not subject to distortion. The inner end surfaces IIIa and IIa of the coupling members are preferably tapered outwardly away from the intermediate member I5 and the surfaces I5a of the intermediate member are similarly tapered outwardly and away from the end surfaces IIIa and IIa of the coupling members. The connecting members I6 contact on their end faces with these surfaces I0, IIa, and, I5a so that the end faces IIa of each connecting member diverges outwardly. l,These connecting rings thus have a gradually increasing thickness toward their outerv margins'zso that there is agreater body of deformable material near the outer circumference of the coupling-,member where the greatest degree of distortion `occurs when the shafts are out of alignment with each other.

In Fig. 2 of the drawings. there is illustrated, upon a somewhat exaggerated scale, the relative positions ofV the parts of the coupling shown in Fig. 1 when the shafts I2 and I3 are out of alignment, thereby causing a substantial distortion of the connecting rings I6 during the rotation of the shafts. It will be observed that one side of each ring is elongated and its opposite circumferential margins drawn in by the stretchingof the material of which it is formed, as shown at I1, While at the opposite side of the ring, the material is compressed and bulges outwardly and inwardly, as shown at I8, due to the inclined position of the-intermediate member I5 which remains without substantial distortion under these conditions. The tendency of the coupling to produce an end thrust upon the shafts is reduced to a minimum because of the limited thickness of the member I6 and, at the same time, these ,members have sufficient body intermedia adjustment of their parts and of the e member I5 through the lack of alignment of the shafts, without setting up substantial transverse pressures on the ends of the shafts. 'I'he forces are thus transmitted through the connecting members I6 primarily by tensile and compressive stresses in the bodies of these members and shearing stresses at the joints between these members and the next adjacent members, without substantial tendency, however, to stretch unduly or permanently elongate the material of which the connecting rings are formed. The coupling members IU and II and the intermediate member I5 may be formed of any hard and substantially u'nyielding material to permit which is capable of being united by vulcanizascribed but is distinguished therefrom in that the intermediate power transmitting member surrounds the end portions of the coupling members to which it is connected by flexible rings of soft material', this form of construction being' particularly adapted for couplings of larger sizes which are intended for use in transmitting an increased amount of power. .In this embodiment, two coupling members 20 and 2I in4 the form of hollow, cylindrical members, are adapted .to be secured upon a pair of substantially aligned shafts 22 and 23, respectively, by means of set screws 24 which engage threaded apertures in the coupling members and bear at their inner ends upon the flat surfaces 222L and 23n of the shafts. The two coupling members 20 and 2I are connected by an intermediate power transmitting member 25, in the form of a cylindrical tube or shell, and two connecting members 28 in the form of rings which are united to the coupling members and to the end portions of the intermediate member. As in the form of construction heretofore described, the coupling members 20 and 2I and the intermediate power transmitting member 25 are preferably formed of hard material, such as steel, brass, hard rubber, or the like, which is capable of being united by vulcanization with the connecting rings 26, these rings being formed preferably of comparatively soft rubber or rubber reinforced by textile fabric, or the like, so that the rings are capable of being distorted to permit compensation for lack of alignment of the connected shafts. The intermediate member 25v is provided at its ends with outwardly diverging annular surfaces 25a adapted to contact with the similar outwardly diverging annular surfaces 28* formed on the connecting members. These connecting members are provided with cylindrical bores 2Gb which are closely fitted by the coupling members 2li and 2| to which they are united by vulcanization or the like. By this arrangement, the connecting members 26 have greater thickness at their outer ends where the greatest distortion of the members take place when the shafts are out of alignment, as illustratedl on a somewhat exaggerated scale in Fig. 4. As here shown, the material of the rings 26 is adapted to stretch and elongate to some extent at certain points due to the misalignment of the shafts, while at diametrically opposite points the material is compressed.

'In the form of the invention shown in Figs. 5 to 8, inclusive, the principles of construction heretofore described are employed but there is provided, in addition, means for connecting one of the coupling members with its shaft in such a mannerthat relative endwise movement is permitted without causing an end thrust to be exerted upon the shafts by the transmission of rubber, or other hard material, capable of being united by vulcanization with the connecting members 36 which are preferably formed of rubber or rubber reinforced by textile fabric, or the like, so that they are capable of being distorted and compressed to compensate for lack of alignment of the shafts. As in the form of the invention shown in Fig. l, the end surfaces 30a and 3 l. `of the coupling members are formed to taper outwardly away from the intermediate member and this intermediate member has its end surfaces 35EIL inclined outwardly away from the coupling members so that the connecting rings 36 increase gradually in thickness from their inner margins outwardly.

'I'he coupling member 30 is secured to the shaft 32 by a set screw 34 passing through a threaded aperture in the coupling member and enga-ging the at surface 32a which is formed on one side of the shaft. The other coupling member 3| is connected to the shaft 33 through an intermediate driving member 31 which is pressed onto the shaftA 33 orotherwise secured in xed position thereon and which occupies the chamber 3|h formed in the coupling member 3| by enlarging the outer portion of the tubular bore extending therethrough. The wall of this chamber 3|'b is provided with a plurality' of longitudinally extending grooves 3|c which are engaged by the longitudinally extending teeth or lugs 31 formed on the driving member 31 which is formed of hard material. These teeth or lugs 31c have a sliding engagement with the grooves 3| c so that when the coupling'is in operation and forces are being transmitted from one shaft to the other, the coupling member 3| is capable of sliding longitudinally on the member 31 to relieve the shafts 32 and 33 ofend thrusts which may be set up by the compression or distortion of the rings 36 or, for example, by the end float of a motor arma-v ture mounted on one of the shafts.

In any form of the invention, the only parts which yield in the plane of rotation under tormentioned, may be used, but it is now considered the preferred practice to form all of the major lparts of rubber, either natural or synthetic, in

two compounds one of whlchbecomes substantially unyielding under the vulcanizing process while the other becomes soft and yielding. The first compound is used in preforming the coupling members and the intermediate member and the second compound is used in forming the comparatively thin connecting rings. These parts are then placed end to end in proper order in a mold and upon the application of suitable temperature and pressure are vulcanized to each other. 'I'he coupling is thus capable of being formed of materials. of low cost and by a simple and inexpensiveprocess of manufacture.

Although certain forms of the inventionhave been shown and described by way of illustration, it will be understood that it maybe constructed in various other forms coming within the scope of the appended claims.

rings each vulcanized to said intermediate member and to one of said coupling members, said rubber rings increasing in thickness from their inner margins outwardly, said intermediate member and said coupling members having tapered end surfaces to correspond to thev increase in thickness of said ringssaid intermediate memintermediate power transmitting member, andrelatively thin deformable resilient connecting members secured to the ends of said intermediate member and to the ends of said coupling members, said connecting members being in the form of annular rings increasing in thickness from their inner margins outwardly, said intermediate member being mounted in a free oating posi- :ign supported entirely by said connecting memrs. 3. The combination in a coupling for connecting two substantially aligned shafts, of a pair of coupling members each adapted to be mounted upon and operatively connected with a separate one of said shafts, an elongated intermediate power transmitting member extending endwise between said coupling members and spaced from each of said coupling members, said coupling members and said intermediate member having oppositely disposed annular end surfaces, and

rubber rings each vulcanized to two of said oppositely disposed end surfaces, said intermediate member being supported entirely by said rubber rings.

LOUIS RICEFIELD. 

